@Orita Issartel for the single tenant that did touch base with you, I would say thanks for letting you know, but that you value an open line of communication with your tenants and that in the future if there is a problem that you'd like to know about any late payment ahead of time because the repercussion is the late fee as well as a 3 day notice. I'd add that you appreciate the response and that you look forward to it being the last time you have this conversation because you look forward to receiving rent on time.
As for your others, it's a little challenging with the first being a bank holiday and it's just not necessarily on everyone's mind. That being said, I would do everything I could to make contact with the tenants: text, email, phone, etc. In all cases I would say the following:
"hi (insert name). Hope you had a wonderful holiday and that you're looking forward to working with me as much as I look forward to working with you. That being said, I have yet to receive your rent. This is a disappointment as it's not a great way to start our relationship. Per our contract, I've asked for rent to be paid on the first with a late fee of $50 to start on the 4th. If I've still not received rent by the 4th, it's an additional $5/day. I doubt that's the math you calculate when you budget paying rent every month and I'd like to help you to not get caught behind on rent. However, it's tough to help if this is how things start. Without rent or a response in writing via text or email, I have no choice but to proceed with an eviction notice on day 3. I would love nothing more than to have a great working relationship moving forward, but the first step is communication so I know what's going on and can do my best to work with you. I'm sorry I haven't heard from you yet, but I do look forward to hearing from you soon as well as receiving rent in addition to the appropriate late fees. Thanks so much and happy New Year from your new landlord."
I always like to target communication with the responsibilities as the follow up. I'd rather have a tenant talk to me than to have a neglectful tenant which leads to a neglected property and minor problems becoming really big problems that become costly to me.